From f4e058fb70eb724da79d4b640db27f0c738ec72b Mon Sep 17 00:00:00 2001
From: yancy <email@yancy.lol>
Date: Wed, 6 Dec 2023 12:28:24 +0100
Subject: [PATCH] wip

---
 src/single_random_draw.rs | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/single_random_draw.rs b/src/single_random_draw.rs
index 0086ca3..ba6c723 100644
--- a/src/single_random_draw.rs
+++ b/src/single_random_draw.rs
@@ -3,10 +3,9 @@
 
 use crate::WeightedUtxo;
 use crate::CHANGE_LOWER;
+use bitcoin::blockdata::effective_value;
 use bitcoin::Amount;
 use bitcoin::FeeRate;
-use bitcoin::SignedAmount;
-use bitcoin::blockdata::effective_value;
 use rand::seq::SliceRandom;
 
 /// Randomly select coins for the given target by shuffling the UTXO pool and
@@ -44,11 +43,11 @@ pub fn select_coins_srd<R: rand::Rng + ?Sized>(
 
     for w_utxo in weighted_utxos {
         let utxo_value = w_utxo.utxo.value;
-        let effective_value: SignedAmount = effective_value(fee_rate, w_utxo.satisfaction_weight, utxo_value)?;
+        let effective_value = effective_value(fee_rate, w_utxo.satisfaction_weight, utxo_value)?;
 
         value += match effective_value.to_unsigned() {
             Ok(amt) => amt,
-            Err(_) => Amount::ZERO,
+            Err(_) => continue,
         };
 
         result.push(w_utxo.clone());
@@ -146,9 +145,10 @@ mod tests {
 
     #[test]
     fn select_coins_skip_negative_effective_value() {
-        let target: Amount = Amount::from_str("1 cBTC").unwrap() - CHANGE_LOWER;
+        let target: Amount = Amount::from_str("2 cBTC").unwrap() - CHANGE_LOWER;
 
-        let mut weighted_utxos: Vec<WeightedUtxo> = vec![WeightedUtxo {
+        let mut weighted_utxos = create_weighted_utxos();
+        let mut negative_eff_value = vec![WeightedUtxo {
             satisfaction_weight: Weight::ZERO,
             utxo: TxOut {
                 value: Amount::from_str("1 sat").unwrap(),
@@ -156,10 +156,16 @@ mod tests {
             },
         }];
 
-        let result = select_coins_srd(target, FEE_RATE, &mut weighted_utxos, &mut get_rng())
+        weighted_utxos.append(&mut negative_eff_value);
+        assert_eq!(weighted_utxos.len(), 3);
+
+        let mut rng = get_rng();
+        let result = select_coins_srd(target, FEE_RATE, &mut weighted_utxos, &mut rng)
             .expect("unexpected error");
 
-        assert!(result.is_empty());
+        let mut expected_utxos = create_weighted_utxos();
+        expected_utxos.shuffle(&mut rng);
+        assert_eq!(result, expected_utxos);
     }
 
     #[test]